设计程序模拟先来先服务FCFS，最短寻道时间优先SSTF，SCAN和循环SCAN算法的工作过程。假设有n个磁道号所组成的磁道访问序列，给定开始磁道号m和磁头移动的方向（正向或者反向），分别利用不同的磁盘调度算法访问磁道序列，给出每一次访问的磁头移动距离，计算每种算法的平均寻道长度。-Design program to simulate a first-come first-serve FCFS, shortest seek time first SSTF, SCAN and SCAN algorithms work cycle process. Suppose there are n number of tracks consisting of tracks access sequence for a given number m, and began to track the direction of head movement (forward or reverse), respectively, using a different track sequence to access the disk scheduling algorithm, given the head of each visit distance, calculate the average seek length for each algorithm.